The present invention relates to integrated circuits (ICs), and more specifically, to an IC interconnect structure having high reliability.
Back-end-of-line (BEOL) interconnects carry high direct current (DC) in advanced integrated circuit (IC) chip technology. The design of BEOL interconnects becomes more challenging in advanced technologies. As IC chip technology advances, self-heating by high current devices raises the temperature of nearby interconnects under circuit operation and makes use of high current carrying BEOL interconnects more challenging. For example, a device that uses high current may heat up an interconnect that is coupled to the device. The high current may cause electromigration degradation of the interconnect (via and/or line), causing shorts or opens. Typically, the above-described problem has been circumvented by widening the interconnect carrying the high current. However, severe current crowding may still exist at the via/line contact interface which is susceptible to electromigration damage.